Monomer double-acting secondary air nozzle

Abstract

The utility model provides a single-body double-acting secondary air nozzle which comprises a shell, a direct blowing air outlet, a deflection air outlet, a direct blowing guide plate, a deflection guide plate and a partition plate, the partition plate divides the shell into an upper channel and a lower channel, the upper channel is fixedly connected with the direct blowing air outlet to form a direct blowing channel, and the lower channel is fixedly connected with the deflection air outlet to form a deflection guide plate. The lower channel is fixedly connected with a deflection air outlet to form a deflection air channel; the secondary air nozzle has the advantages that the single secondary air nozzle is divided into the direct blowing air outlet and the deflection air outlet, the two outlets are spaced by a certain distance in the height direction and are of a horn mouth structure, and two air flows do not interfere with each other when being ejected out of the secondary air nozzle and are gradually mixed after passing through a certain distance; delayed mixing of deflection secondary air flow and main air flow is really achieved.

Description

Technical Field

[0001] The utility model relates to the technical field of secondary air nozzles, in particular to a single-body double-acting secondary air nozzle. Background Art

[0002] With the rapid development of new energy power generation technology in my country, the proportion of thermal power generation has gradually decreased. Thermal power units will mainly become peak-shaving units to ensure the consumption of new energy power. The operating stability and reliability of these thermal power units are crucial, among which the boiler, as one of the main engines of the power plant, plays a key role. Adjustment of the secondary air of the burner is the main means to cope with load changes, fuel changes, reduce NOx emissions and prevent high-temperature corrosion in the daily operation of the boiler. In the design of boiler burners using tangential burner technology, the secondary air is generally designed into two parts, one for direct blowing and the other for deflected wind. By adjusting the air volume distribution ratio of the two secondary airs, the boiler combustion conditions can be adjusted, and then the operating parameters of the boiler can be adjusted.

[0003] In the existing tangential burner design, a single secondary air nozzle in the main burner area often has both direct air and deflected air. Limited by the total height of the burner and the height of the wind box compartment, the two parts of secondary air are divided into two upper and lower airflows by only one partition. This design structure results in no obvious boundary between the direct airflow and the deflected airflow, which begin to diffuse and mix into one airflow at the outlet of the secondary air nozzle, and cannot achieve the theoretical design purpose of separating the direct air and the deflected air, which greatly reduces the actual effect of the secondary air adjustment. Since the smaller the boiler capacity, the smaller the total height of the burner and the primary air spacing, and the smaller the height of the wind box compartment where the secondary air nozzle is located, the above problem is particularly prominent in tangential combustion boilers of 350MW and below. If a single secondary air nozzle is divided into two small nozzles, it will have the adverse effects of increased costs and increased air leakage ratio. Utility Model Content

[0004] In order to overcome the above problems existing in the prior art, the utility model provides a single-body double-acting secondary air nozzle.

[0005] The utility model discloses a single double-acting secondary air nozzle, comprising a shell, a direct blowing air outlet, a deflected air outlet, a direct blowing guide plate, a deflected guide plate and a partition plate, wherein the partition plate divides the shell into an upper channel and a lower channel, the upper channel is fixedly connected to the direct blowing air outlet to form a direct blowing air channel, the lower channel is fixedly connected to the deflected air outlet to form a deflected air channel, a direct blowing guide plate is arranged in the direct blowing air channel, a deflected guide plate is arranged in the deflected air channel, and the direct blowing air outlet and the deflected air outlet are of a tapered bell-mouth structure.

[0006] On this basis, the deflected wind angle β ranges from 2° to 20°.

[0007] On this basis, the secondary air nozzle can be integrally cast using a casting technique, or can be manufactured using steel plate welding.

[0008] On this basis, the design angle α of the direct air outlet and the deflected air outlet is ≥20°, and the distance H between the direct air outlet and the deflected air outlet is ≥100mm.

[0009] On this basis, the direct air outlet is located above or below the deflected air outlet.

[0010] Compared with the prior art, the utility model has the following beneficial effects: a single secondary air nozzle is divided into two outlets, namely, direct blowing air and deflected air. The two outlets are spaced a certain distance apart in the height direction and adopt a bell-mouth structure. When the two airflows are ejected from the secondary air nozzle, they do not interfere with each other and gradually mix after a certain distance, thus truly realizing the delayed mixing of the deflected secondary airflow and the main airflow; the bell-mouth structure can compensate for the airflow diffusion angle and increase the distance between the mixing point of the two airflows and the nozzle. This structure enables a single nozzle to provide two secondary airflows with different functions, and avoids the early mixing of the two airflows, thus improving the air classification effect and wind-powder encapsulation effect of the deflected secondary airflow, and enhancing its ability to reduce NOx, prevent high-temperature corrosion, and adjust the size of the combustion cutting circle. When the type of coal changes and the load of the unit changes, it is beneficial to improve the convenience and accuracy of combustion adjustment. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 This is a schematic diagram of the secondary air nozzle structure of the utility model;

[0012] Figure 2 This is a schematic diagram of the side structure of the secondary air nozzle of the utility model;

[0013] Figure 3 yes Figure 1 AA structural diagram;

[0014] Figure 4 yes Figure 1 BB structural diagram;

[0015] Figure 5 is a schematic structural diagram of Embodiment 1;

[0016] Figure 6 is a schematic structural diagram of Embodiment 2;

[0017] In the figure: 1, shell, 2, direct air outlet, 3, deflected air outlet, 4, direct air guide plate, 5, deflected air guide plate, 6, partition plate. DETAILED DESCRIPTION

[0018] The present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0019] Example 1

[0020] The utility model discloses a single double-acting secondary air nozzle, referring to Figure 1 , Figure 2 , Figure 3 and Figure 4 , comprising a shell 1, a straight air outlet 2, a deflected air outlet 3, a straight air guide plate 4, a deflected air guide plate 5 and a partition plate 6, the partition plate 6 divides the shell 1 into an upper channel and a lower channel, the upper channel is fixedly connected to the straight air outlet 2 to form a straight air channel, the lower channel is fixedly connected to the deflected air outlet 3 to form a deflected air channel, a straight air guide plate 4 is arranged in the straight air channel, and a deflected air guide plate 5 is arranged in the deflected air channel. The straight air outlet 2 and the deflected air outlet 3 are of a tapered bell-mouth structure, and the deflected air angle β ranges from 2° to 20°, which is determined according to the characteristics of the boiler fuel and the design diameter of the imaginary tangent circle. When the boiler fuel has strong slagging property, β should be selected as a smaller value; when the boiler fuel has weak slagging property, the high-temperature corrosion risk is greater or the ignition property is poor, β should be selected as a larger value.

[0021] In this embodiment, the direct air outlet 2 is located at the upper part, and the deflected air outlet 3 is located at the lower part.

[0022] The secondary air nozzle can be cast in one piece using casting technology, or it can be manufactured by welding steel plates.

[0023] In order to ensure that the airflow intersection point is as far away from the nozzle end as possible, the design angle α of the direct air outlet 2 and the deflected air outlet 3 is ≥20°, and the distance H between the direct air outlet 2 and the deflected air outlet 3 is ≥100mm.

[0024] The working principle of the utility model is: in actual use, refer to Figure 5After the secondary air enters the secondary air nozzle, it is divided into an upper and lower part by a partition plate 6, and enters the direct blowing air channel and the deflected wind channel respectively, and is ejected from the direct blowing air outlet 2 and the deflected wind outlet 3 respectively. The design angle α of the direct blowing air outlet 2 and the deflected wind outlet 3 is ≥20°, and the distance between the two outlets is H ≥100mm. Under the above design parameters, when the two airflows are ejected from the secondary air nozzle, the diffusion angle is small, and the airflow roots do not interfere with each other. They are gradually mixed after a long distance, and the delayed mixing of the deflected secondary airflow and the main airflow is truly realized. The bell-mouth structure is adopted, and the bell-mouth structure can compensate for the airflow diffusion angle and increase the length of the mixing point of the two airflows from the nozzle. The two jets begin to mix after being away from the nozzle outlet for a certain distance, which is conducive to the deflection angle of the deflected secondary air jet, avoiding the early interference of the direct blowing wind on the deflected wind, so that the deflected secondary air can effectively play its role in air classification and increasing the oxygen content outside the combustion fireball. The gap between the two airflows forms a differential pressure balancing channel, which can achieve pressure balance on both sides of the secondary airflow, reduce the deflection of the airflow caused by the pressure difference on both sides, enhance the rigidity of the airflow, avoid premature mixing of the two airflows, and improve the air classification effect and wind powder enveloping effect of the deflected secondary airflow, thereby enhancing its ability to reduce NOx, prevent high-temperature corrosion and adjust the size of the combustion cutting circle; when the coal type changes and the unit load changes, it is beneficial to improve the convenience and accuracy of combustion adjustment.

[0025] Example 2

[0026] refer to Figure 6 , is a structural schematic diagram of another single double-acting secondary air nozzle. The difference between this embodiment and embodiment 1 is that the direct air outlet 2 is located at the lower part, the deflected air outlet 3 is located at the upper part, the deflected wind is tilted to the other side, and the other structures are the same as embodiment 1.

[0027] In the description of the present invention, it should be understood that the terms "coaxial", "bottom", "one end", "top", "middle", "the other end", "upper", "one side", "top", "inside", "front", "center", "both ends" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0028] In the present utility model, unless otherwise clearly stipulated and limited, the terms such as "installation", "setting", "connection", "fixation", "screwing", "pad installation" and the like should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral one; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be the internal connection of two elements or the interaction relationship between two elements. Unless otherwise clearly defined, ordinary technicians in this field can understand the specific meanings of the above terms in the utility model according to the specific circumstances.

[0029] The above description shows and describes the preferred embodiments of the utility model. As mentioned above, it should be understood that the utility model is not limited to the form disclosed herein, and should not be regarded as excluding other embodiments, but can be used in various other combinations, modifications and environments, and can be modified within the scope of the utility model concept described herein through the above teachings or the technology or knowledge of the relevant field. The changes and modifications made by those skilled in the art do not depart from the spirit and scope of the utility model, and should be within the scope of protection of the claims attached to the utility model.

Claims

1. A single double-acting secondary air nozzle, characterized in that: The invention comprises a shell (1), a straight-blowing air outlet (2), a deflected air outlet (3), a straight-blowing guide plate (4), a deflected guide plate (5) and a partition plate (6); the partition plate (6) partitions the shell (1) into an upper channel and a lower channel; the upper channel is fixedly connected to the straight-blowing air outlet (2) to form a straight-blowing air channel; the lower channel is fixedly connected to the deflected air outlet (3) to form a deflected air channel; the straight-blowing guide plate (4) is arranged in the straight-blowing air channel; the deflected guide plate (5) is arranged in the deflected air channel; the straight-blowing air outlet (2) and the deflected air outlet (3) are of a tapered bell-mouth structure.

2. The single double-acting secondary air nozzle according to claim 1 is characterized in that: The deflected wind angle β ranges from 2° to 20°.

3. The single-body double-acting secondary air nozzle according to claim 1 is characterized in that: The secondary air nozzle is integrally cast by using a casting technology, or is manufactured by welding steel plates.

4. The single double-acting secondary air nozzle according to claim 2 is characterized in that: The design angle α of the direct air outlet (2) and the deflected air outlet (3) is ≥20°, and the distance H between the direct air outlet (2) and the deflected air outlet (3) is ≥100 mm.

5. The single double-acting secondary air nozzle according to claim 1 is characterized in that: The direct air outlet (2) is located above or below the deflected air outlet (3).

Images